This is a larger more powerful beam tetrode audio valve than the 6V6 receiver types. This was used for audio amplifiers and also for stabilised power supplies. Heathkit used a pair in parallel to produce a 400 volt 100mA supply.

The construction is of a traditional flat cathode with a zig-zag grid supported on notched rods surrounding the cathode. The beam plates are vertical [ shaped sections to the edges of the grid assembly. The anode is an open vertical box that encloses the rest of the electrodes.

The wide glass tube envelope is 34 mm in diameter and, excluding the IO base pins, is 91 mm tall.

 
Pin Connections

IO	1	2	3	4	5	6	7	8
	m	h	a	g2	g1	nc	h	k

 
Absolute Maximum Operating Conditions

Beam Tetrode	Vh	Ah	Va	Vs	Vg	mAa	mAs	ra	gm	Pout	D
	6.3	0.9	350	250	-18	54	2.5	33K	5.2	11W	15%

Thanks to Frank Philipse for supplying the above datasheet

This exhibit was last updated on 30 March 2008 {find valves by name}